package com.itheima.reggie.filter;

import com.alibaba.fastjson.JSON;
import com.itheima.reggie.common.BaseContext;
import com.itheima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * 检查用户是否已完成登录
 */
@Slf4j
@WebFilter(filterName = "LoginCheckFilter", urlPatterns = "/*")    //javaWeb过滤器
public class LoginCheckFilter implements Filter {
    // 路径匹配器  支持通配符解析
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();


    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        //获取执行的线程信息
        long id = Thread.currentThread().getId();
        log.info("线程id为：{}", id);


        //注意：如果访问request里面的方法，父接口没有则转为使用子接口
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;

        //1、获取本次请求的URI
        String requestURI = request.getRequestURI();

        log.info("拦截到请求：{}", requestURI);

        //定义不需要拦截处理的请求路径
        String[] urls = new String[]{
                "/employee/login",
                "/employee/logout",
                "/backend/**",
                "/front/**",
                "/common/**",
                //放行移动端的资源
                "/user/sendMsg",
                "/user/login",
                "/pay/fallback"
        };
        //注意：
        //  @WebFilter(filterName = "loginCheckFilter",urlPatterns = "/*")
        //      这里的/*是由tomcat解析，支持任意路径的匹配
        //  /backend/** 这里的通配符是由spring工具类 AntPathMatcher 解析
        //      /backend/* 里面的*代表的是一层目录任意
        //      /backend/** 里面的*代表的是多层目录任意   例如：/backend/page/login/login.html

        //2、判断本次请求是否需要拦截处理
        boolean check = check(urls, requestURI);

        //3、如果不需要处理，直接放行
        if (check) {
            log.info("本次{}请求不需要处理", requestURI);
            filterChain.doFilter(request, response);
            return;
        }

        //4、判断登录状态，如果已登录，则直接放行
        if (request.getSession().getAttribute("employee") != null) {
            log.info("用户已登录，用户Id为：{}", request.getSession().getAttribute("employee"));

            //登录成功，将登录人id写入到ThreadLocal中
            Long employeeId = (Long) request.getSession().getAttribute("employee");
            BaseContext.setCurrentId(employeeId);

            filterChain.doFilter(request, response);
            return;
        }

        //4-2、针对移动端、判断登录状态，如果已登录，则直接放行
        if (request.getSession().getAttribute("user") != null) {
            log.info("用户已登录，用户id为：{}", request.getSession().getAttribute("user"));

            //登录成功将登录人id写入到ThreadLocal中
            Long userId = (Long) request.getSession().getAttribute("user");
            BaseContext.setCurrentId(userId);

            filterChain.doFilter(request, response);
            return;
        }

        //5、如果未登录，则返回未登录结果，通过输出流方式向客户端页面响应数据
        log.info("用户未登录");
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
        return;


    }

    /**
     * 路径匹配，检查请求是否需要放行
     *
     * @param urls
     * @param requestURI
     * @return
     */
    public boolean check(String[] urls, String requestURI) {
        for (String url : urls) {
            boolean match = PATH_MATCHER.match(url, requestURI);
            if (match) {
                return true;
            }
        }
        return false;
    }
}
